Methods that find the associated contours in image recordings for a given tracer data record are known. In the process, use is made of image-based methods such as pattern searches or template matching. Reference is made to the disclosure of DE 10 2011 115 239 B4 in exemplary fashion. A disadvantage of this solution is that the tracer data record, and hence the worn spectacles, must be known in order to find the contours in the recorded images. However, the typical workflow of the optician is such that tracer data of a frame are only produced once the customer has already selected the spectacles to be purchased. This means that these data are not available for all spectacles in the store when the customer stays in the store. Usually, the tracer data are additionally only determined in the evening after the customer has already left the store, so that there is no need for the customer to wait for this. Thus, the related art would require tracer data to be produced first before the centration can be carried out; this would change the workflow of the optician and take up the customer's time. Additionally, it is also inconvenient if every optician must store the tracer data record for each frame. Additionally, these data are typically only available in two-dimensional fashion but are usually required in three dimensions.